Osamu Ogasawara is a Japanese programmer and game designer, known for his work at Nintendo, particularly within the Research & Development 1 (R&D1) division. His career is closely tied to the development of two iconic series: *Metroid* and *Wario Land*. He served as director for *Metroid II: Return of Samus* on the Game Boy and contributed as a programmer to the acclaimed *Super Metroid* for the SNES, solidifying the foundations of the series. However, his most significant contribution is considered to be the creation and direction of the *Wario Land* series. He directed the inaugural title, *Wario Land: Super Mario Land 3*, and its sequels, *Virtual Boy Wario Land* and *Wario Land II*. Through these games, Ogasawara was instrumental in defining Wario's unique gameplay mechanics, transforming him from an antagonist into a popular anti-hero and protagonist, leaving a lasting mark on the history of Nintendo platformers.